Method for shaping tube ends

ABSTRACT

A method is disclosed for the fabrication of tampon applicator tubes in which the forward ends of thin-walled tube blanks are crimped to provide a plurality of longitudinal fold lines, folded and compressed to form a plurality of pleats, exercised to weaken the fold lines to facilitate ejection of the tampon and refolded under compression to form a pleated, generally conically shaped forward tube end having a relatively smooth exterior surface.

United States Patent Voss et al.

[ METHOD FOR SHAPING TUBE ENDS [72] Inventors: Joseph A. Voss, Denver, Colo.; Carl W. Johnson, Neenah, Wis.

[73] Assignee: Kimberly-Clark Corporation,

Neenah, Wis.

[22] Filed: Dec. 10, 1970 [2-1] Appl. No.: 97,047

Related (1.8. Application Data [62] Division of Ser. No. 690,00l, Dec. 12, 1967,

Pat. No. 3,568,577.

[52] US. Cl ..93/94 FC, 93/36.] [5 1] Int. Cl ..B3lc 7/02 [58] Field of Search ..93/36.1, 36, 94 FC, 77, 36.5

[56] References Cited UNITED STATES PATENTS Thompson et al. ..93/94 FC [451 Aug. 15, 1972 Primary Examiner-Bemard Stickney AttorneyFraser & Bogucki ABSTRACT A method is disclosed for the fabrication of tampon applicator tubes in which the forward ends of thinwalled tube blanks are crimped to provide a plurality of longitudinal fold lines, folded and compressed to form a plurality of pleats, exercised to weaken the fold lines to facilitate ejection of the tampon and refolded under compression to form a pleated, generally conically shaped forward tube end having a relatively smooth exterior surface.

4 Claims, 45 Drawing Figures PATENTEDAUB 15 1972 SHEET OlUF 21 FlG.-3

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1. A method for shaping the end portion of a tube comprising: crimping said end portiOn to provide a plurality of longitudinally disposed folds; folding and compressing said crimped end portion into a plurality of pleats, thereby forming said tube end into a generally conical shape; penetrating said folded forward end of said tube with male die means to at least partially unfold said forward end; and, refolding and compressing said forward end portion into said pleated, generally conical shape.
 2. A method, as defined in claim 1, in which: said forward end portion is unfolded progressively in successive stages.
 3. A method, as defined in claim 1, in which: said tube end is substantially fully unfolded in a single operation by positioning said male die means within said tube and moving said die means forwardly to penetrate said forward end.
 4. A method, as defined in claim 1, which includes: forming a small, centrally oriented aperture in said forward end portion of said tube during the refolding step. 